The dual mode of ventilation ′pressure-controlled ventilation-volume guaranteed′ does not provide anymore benefit in obese anesthetized patients

Background Ventilatory strategies aim at the prevention of atelectasis and the improvement of oxygenation, but yet none is optimal. On comparing pressure-controlled ventilation (PCV) with volume-controlled ventilation (VCV) with the same tidal volume and inspiratory time, PCV tends to produce higher mean airway pressures, and thereby improves oxygenation. However, volume-targeted ventilators (VTV) allow to set the tidal volume directly. In order to deliver that volume. We compared PCV and pressure-controlled ventilation volume guaranteed (PCV-VG) with regard to the airway pressures produced when aiming to achieve the same tidal volume. Patients and methods Thirty obese ASA I-III patients scheduled for abdominal surgery were ventilated with PCV for 45 min; then, the PCV-VG mode was applied to all patients with the same parameters, targeting the same tidal volume of conventional PCV during the first phase. The plateau pressure and the mean airway pressure were recorded and compared between both modes. Vital signs, EtCO 2 , SpO 2 , arterial blood gases, and the oxygenation index were compared. Results No difference was observed between both modes of ventilation in terms of the plateau airway pressure (34.2 ΁ 1.8 vs. 34.1 ΁ 2.9 cmH 2 O, P = 0.484) and the mean airway pressure (13.4 ΁ 1.6 vs. 13.2 ΁ 1.8 cmH 2 O, P = 0.326). No significant difference was observed between PCV and PCV-VG with regard to the hemodynamics, EtCO 2 , and SpO 2 . No significant change was observed in the arterial blood gas analysis including pH (7.39 ΁ 0.3 versus 7.4 ΁ 0.2 with P value 0.204), PaCO 2 (30.8e 0.204) change in 0.2 with P value 0.06), PaO 2 (155.8 0.06)) change in0.2 with blood P value 0.316) and oxygenation index (4.34 oxygenation index.2 with bP value 0.176). ConclusionNo significant difference was observed between both modes of ventilation (PCV vs. PCV-VG) in obese patients.